Astronomy and Astrophysics – Astrophysics – Galaxy Astrophysics
Scientific paper
2011-01-11
Astronomy and Astrophysics
Astrophysics
Galaxy Astrophysics
A&A Accepted, spelling of author's name corrected (Neill)
Scientific paper
Using archival observations recorded over a 5+ year timeframe with the NASA Galaxy Evolution Explorer (GALEX) satellite, we present a study of the ultraviolet (UV) variability of 4360 quasars of redshifts up to z=2.5 that have optical counterparts in the Sloan Digital Sky Survey DR5 spectroscopic catalog. The observed changes in both the far UV (FUV: 1350-1785A) and near UV (NUV: 1770-2830A) AB magnitudes as a function of time may help differentiate between models of the emission mechanisms thought to operate in these active galaxies. A list of NUV and FUV variable quasars was derived from the UV light-curves of sources with 5 or more observational visits by GALEX that spanned a time-frame greater than 3 months. By measuring the error in the derived mean UV magnitude from the series of GALEX observations for each source, quasars whose UV variability was greater than the 3-sigma variance from the mean observed value were deemed to be (intrinsically) UV variable. This conservative selection criterion (which was applied to both FUV and NUV observations) resulted in identifying 550 NUV and 371 FUV quasars as being statistically significant UV variable objects.
Neill James D.
Welsh Barry Y.
Wheatley Jonathan M.
No associations
LandOfFree
GALEX observations of quasar variability in the ultraviolet does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with GALEX observations of quasar variability in the ultraviolet, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and GALEX observations of quasar variability in the ultraviolet will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-161117